Josephson Junction as an LC-environment

by


René Lindell, Jari Penttilä, Pertti Hakonen and Mikko Paalanen


Low Temperature Laboratory, 
Helsinki University of Technology



Josephson junctions are known to have nonlinear inductance. We study 

the manifestation of this inductance when Josephson junctions are used 

as an environment to a mesoscopic tunneling junction. In the linear regime, the 

Josephson junction is a harmonic oscillator as the inductance is coupled 

to its capacitance. P(E)-theory provides a framework in which mesoscopic 

junctions in different electromagnetic environments can be analyzed theoretically. 

Resonance peaks, whose positions depend on the Josephson energy of the environmental

junctions, are expected in the subgap region of the IV-curve.


In our samples, done using e-beam lithography and shadow evaporation, we

employ a four wire configuration with a tunable SQUID-loop in each measuring

lead. Preliminary results obtained on devices with small critical currents are

discussed.